Tension device



W. B. FREEMAN TENSION DEVICE May 17, 1938.

Filed Nov. 10, 1936 I, .I 2 I; ll 20 "-1 [1Q tim L i i LL J A I ZIIAVJ /M M Patented May 17, 1938 UNITED STATES PATENT OFFICE TENSION DEVICE Application November 10, 1936, Serial No. 110,067

1 Claim.

This invention relates to tension devices such as are used for applying tension to strip material.

The principal objects of the invention are to provide simplicity of structure, a high range of adjustability, and accuracy of adjustment.

Other objects will appear from the following description and the accompanying drawing.

Of the drawing:

Fig. 1 is a side elevation of the device in its preferred form.

Fig. 2 is a plan view of the same.

Fig. 3 is a sectional view taken on line 33 of Fig. 1.

Referring to the drawing, the numeral ll] designates a stationary frame member. A moveable plate II is slidably mounted upon the face of the frame member and is provided with gibs l 2, i3 for guiding it in its sliding movement. Frame 10 is provided with a plurality of spaced strip engaging members l4, preferably in the form of stationary pins. Plate H is provided with simi lar strip engaging members l5 arranged in interoalated relation to members l4, and plate II is formed with clearance slots Hi to clear the members l4 during its movement.

In order to provide for adjusting plate I I along frame H], a plurality of feed screws ll, l8 are rotatably mounted in bearings I9, 20, fixed to the frame Ill and with their axes parallel and corresponding to the desired path of movement. Threaded nuts 2|, 22 are fixed to the plate I I and extend through clearance slots 23, 24 formed in the frame In so as to engage the feed screws.

To provide for simultaneous movement of the feed screws, a pair of sprockets 25, 26, are fixed thereto and connected by a chain 21. A hand wheel 28, fixed to one of the feed screws permits hand adjustment.

In the drawing, a plurality of strips, or cords, 30 are shown as being simultaneously tensioned by being led in a sinuous path about the ten- Sioning pins l4, l5. By adjustment of the pins so as to raise pins l5 above the plane of pins I4, 5

the strips may be threaded through the device without tension. As the pins I5 are lowered, the tension is gradually increased as arcuate contact with the pins increases. The decrease in the angles between successive reaches of the strip 10 from pin to pin, increases the pressure of the strips against the pins, while at the same time, the angular contact of the strips against the pins is increased.

Where the pins are supported from one end only, as shown in the drawing, the material may be readily threaded through the tension device.

I claim:

Apparatus for applying tension to a reach of 20 for moving said carriage positively forward and 30 positively back to change the relation of the sets of pins to each other while maintaining rigidly their spacing at any position, and means for driving the feeding screw and nut elements together,

said tension pins being supported at one end only 35 so as to permit lateral insertion of the material therebetween without disturbing the adjustment of the tension pins.

WALTER B. FREEMAN. 

